Optimal Marathon Training

Of the many possible combinations of speed and distance that you can do in training, a few provide the optimal stimuli for physiological improvements for the marathon. The most effective types of marathon training are described below. These workouts form the key sessions in Pete’s training programs.

I. Tempo Runs:

The most effective way to improve your lactate threshold is to run at your current lactate threshold pace, or a few seconds per mile faster. This can be done either as one continuous run (tempo runs) or as a long interval session at your lactate threshold pace (called cruise intervals or LT intervals).

These workouts make you run hard enough that lactate is just starting to accumulate in your blood. When you train at a lower intensity, a weaker stimulus is provided to improve your lactate threshold pace. When you train faster than current lactate threshold pace, you’ll accumulate lactate rapidly, so you won’t be training your muscles to work hard without accumulating lactate. During these workouts, the more time that you spend at your lactate threshold pace, the greater the stimulus for improvement.

Lactate threshold training should be run at close to the pace that you could currently race for one hour. For serious marathoners, this is generally 15K to 20K race pace. This should be the intensity at which lactate is just starting to accumulate in your muscles and blood. In terms of heart rate, lactate threshold typically occurs at 80 to 90 percent of maximal heart rate, or 76 to 88 percent of heart rate reserve in well-trained runners.

You can do some of your tempo runs in low-key races of 4 miles to 10K, but be careful not to get carried away and race all out. Remember that the optimal pace to improve lactate threshold is your current LT pace, and not much faster.

A typical training session to improve lactate threshold consists of a 15- to 20-minute warm-up, followed by a 20- to 40-minute tempo run and a 15-minute cooldown. The lactate threshold workouts in my training programs mainly fall within these parameters, although some programs include one longer tempo run in the 7-mile range. LT intervals are typically two to five repetitions of five minutes to two miles at lactate threshold pace with two or three minutes between repetitions.

For runners competing in shorter races, tempo runs and LT intervals are both excellent ways to prepare. For marathoners, however, tempo runs are preferable to LT intervals. After all, the marathon is one long continuous run, and tempo runs simulate marathon conditions more closely than do LT intervals. 

There’s both a physiological and a psychological component to the advantage of tempo runs. The extra mental toughness required to get through a tempo run when you may not be feeling great will come in handy during the marathon.


II. Long Runs:

Your long runs should be run 10 to 20 percent slower than your goal marathon race pace. This will ensure that you’re running with a similar posture and are using similar muscle patterns as when you run at marathon pace. If you do your long runs much slower than this, then you’ll run the risk of not being prepared for the marathon. Slow long runs reinforce poor running style and do a poor job of simulating the demands of the marathon. If you run your long runs too fast, of course, then you’ll run the risk of leaving your marathon performance out on your training loops, because you’ll be too tired for your other important training sessions. If you use a heart monitor, long run pace should put you in the range of 73 to 83 percent of maximal heart rate, or 65 to 78 percent of your heart rate reserve.

Almost all of Pete’s marathon training programs include a long run of at least 17 miles most weeks, and a second long run each week of 12 to 15 miles. The longest run in any of the programs is 24 miles, because longer runs have too high a risk of injury. A typical pattern is to build the long runs up to 20 miles approximately 10 to 12 weeks before the marathon and then to do 20 to 22 mile runs two out of every three weeks until three weeks before the marathon.

The first few miles of your long runs can be done slowly, but by 5 miles into your long run, your pace should be no slower than 20 percent slower than marathon race pace. Then gradually increase your pace until you’re running approximately 10 percent slower than marathon race pace during the last 5 miles of your long runs. This makes for an excellent workout and provides a strong stimulus for physiological adaptations such as increased glycogen storage. In terms of heart rate, you would run the first few miles at the low end of the recommended intensity range, and gradually increase your effort until you reach the high end of the range during the last few miles. These workouts are difficult enough that you should schedule a recovery day the day before, and one or two days after your long runs.

If you do long runs in this intensity range, a 22-mile run will take approximately the same amount of time as your marathon. By running for the length of time you hope to run the marathon, you also provide psychological reinforcement that you can run at a steady pace for that amount of time.

Sample Long Run Paces

Using the suggested intensity range of 10 percent to 20 percent slower than marathon goal pace, here are suggested long run paces for a wide range of marathoners.


Goal Pace

Early Part of Long Run
(20% Slower than Goal Pace)

Latter Part of Long Run
(10% Slower than Goal Pace)






















III. Workouts to Improve Your VO2 max

The most effective running intensity to improve your VO2 max is 95 percent to 100 percent of your current VO2 max. Well-trained runners can run at VO2 max pace for about eight minutes. Ninety-five percent to 100 percent of VO2 max coincides with current 3,000 meter to 5,000 meter race pace. This typically coincides with an intensity of approximately 94 to 98 percent of maximal heart rate or 93 to 98 percent of heart rate reserve. Running your intervals at this pace or intensity is part of the optimal strategy to improve your VO2 max.

The stimulus to improve your VO2 max is provided by the amount of time you accumulate during a workout in the optimal intensity range of 95 percent to 100 percent of VO2 max. This has implications for how best to structure your VO2 max sessions. Consider two workouts that each include 6,000 meters of intervals—one of 15 x 400 meters, the other of 5 x 1200 meters. When you run 400-meter repetitions, you’re in the optimal zone for perhaps 45 seconds per interval. If you do 15 repetitions, you would accumulate just over 11 minutes at the optimal intensity. When you run longer intervals, you are in the optimal intensity zone much longer. During each 1,200-meter interval, you would be in the optimal intensity zone for three to four minutes, and would accumulate 15 to 20 minutes in that zone during the workout. This would provide a stronger stimulus to improve your VO2 max.

The optimal duration for VO2 max intervals for marathoners is approximately two to six minutes. Intervals in this range are long enough that you accumulate a substantial amount of time at VO2 max pace during each interval, but short enough that you can maintain 95 percent to 100 percent of VO2 max. Intervals for marathoners should generally be between 800 meters and 1,600 meters/one mile. Sometimes, such as the week of a tune-up race, 600-meter repeats also have a place as a VO2 max session during marathon preparation.

The total volume of the intervals in a marathoner’s VO2 max session should be 5,000 to 10,000 meters, with most workouts in the range of 6,400 to 8,000 meters. Any combination of repetitions of 800 meters to 1,600 meters will provide an excellent workout. Longer intervals (e.g., 1,200s or 1,600s) make for a tougher workout, physically and psychologically, and shouldn’t be avoided.

The optimal amount of rest between intervals is debatable. One school of thought is to minimize the rest so that your metabolic rate stays high during the entire workout. This strategy makes for very difficult workouts, but runs the risk of shortening your workouts. Another school of thought is to allow your heart rate to decrease to 70 percent of your maximal heart rate or 60 percent of your heart rate reserve during your recovery between intervals. For the lower-tech crowd, a good rule of thumb is to allow 50 percent to 90 percent of the length of time it takes to do the interval for your recovery. For example, if you’re running 1,000-meter repeats in 3:20, you would run slowly for 1:40 to 3 minutes between intervals.

Sample VO2 Max Workouts

  • 6 to 10 x 800 meters

  • 5 to 10 x 1,000 meters

  • 4 to 8 x 1,200 meters

  • 3 to 6 x 1,600 meters

  • Various “ladder” combinations such as 800 m, 1000 m, 1200 m, 1600 m, 1200 m, 1000 m, 800 m

IV. Training at Marathon Race Pace

Long runs at marathon race pace prepare you most directly for the demands of the marathon. The principle of specificity of training states that the most effective way to prepare for an event is to simulate that event as closely as possible in training. The closest way to simulate a marathon, of course, is to run 26.2 miles at marathon pace. Unfortunately, long runs at marathon pace are very hard on the body. If you run too far at marathon pace, the required recovery time will negate the benefits of the effort. Similarly, if you do long runs at marathon pace too often, you will greatly increase your likelihood of self-destructing through injury or overtraining.

Most of Pete’s marathon training programs include one or two runs of 12 to 15 miles (usually during a longer run) at goal marathon race pace. These runs are the most specific marathon preparation that you’ll do. The intention is to stress your body in a similar way to the marathon, but to limit the duration so that your required recovery time is held to a few days. On these runs, use the first few miles to warm up, then finish the run with the prescribed number of miles at marathon race pace. In addition to the physiological and psychological benefits these runs impart, they’re an excellent opportunity to practice drinking and taking energy gels at race pace.

Where should you do your marathon pace runs? Races of the appropriate distance are ideal — you’ll have a measured course, plenty of aid stations and other runners to work with. As with doing tempo runs in races, though, be sure to limit yourself to the day’s goal and run them no faster than is called for.

If you can’t find a race of suitable length in which to do your marathon-pace runs, try to run at least part of them over a measured course, so that you can get feedback about your pace. A reasonable way to check pace is to do one or two miles in the middle of a road race course that has markers painted on the road. Similarly, many bike paths have miles marked. Your entire run needn’t be over a precisely calibrated course, but try to include at least a few stretches where you can accurately assess your pace, and then rely on perceived exertion or heart rate during the other parts of the run.

Learn your goal marathon’s topography and attempt to mimic it on your marathon-pace runs. Many runners do this when preparing for courses with obvious quirks, such as Boston, but the principle applies for all marathons. Flat courses such as Chicago also take their toll, because your leg muscles are used exactly the same way from start to finish.

V. Short Intervals (Strideouts):

Running short repetitions quickly but with relaxed form helps train your muscles to eliminate unnecessary movements and maintain control at fast speeds. Along with improved running form, you’ll gain power in your legs and trunk that may also contribute to improved running economy. These intervals are short enough, and done with sufficient rest between, that lactate levels remain moderate throughout the workout. As a result, they won’t interfere with your more marathon-specific workouts.

A typical session is 12 repetitions (or 2 sets of 6 repetitions with 3-5 minutes between sets) of 100 meters in which you accelerate up to full speed over the first 70 meters and then float for the last 30 meters. Another often-used session is 10 repetitions (or 2 sets of 5 repetitions) of 30 to 45 seconds, in which the acceleration is not as dramatic.

It’s critical to remain relaxed during these repetitions. Avoid clenching your fists, lifting your shoulders, tightening your neck muscles, etc. Concentrate on running with good form, and focus on one aspect of good form, such as relaxed arms or complete hip extension, during each interval.

These sessions aren’t designed to improve your cardiovascular system, so there’s no reason to use a short rest between accelerations. A typical recovery is to jog or even walk the same distance between repetitions. The most important considerations are to maintain good running form and to concentrate on accelerating powerfully during each repetition.


Text copyright © by Pete Pfitzinger
Pete Pfitzinger is an exercise physiologist with over 20 years of coaching experience, Pete adheres to the principle that every runner is unique and that training programs must be tailored to the athlete's individual strengths and weaknesses. 

Pete Pfitzinger is co-author of two successful books:

Road Racing for Serious Runners
Road Racing for Serious Runners
Buy it here

Advanced Marathoning
Advanced Marathoning
Buy it here

This article has informational purpose and  isn't a substitute for professional advice.

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